Causes Analysis on Surface Cracks of Brake Wheel of a Gantry Crane

During the safety assessment of the gantry crane used for more than 15 years, lots of surface cracks were found on the brake wheel. The brake wheel was inspected to analyze the causes of cracks by means of macroscopic examination, chemical composition analysis, hardness test and metallographic examination. The results show that the inclusions, cracks and other defects were formed in the brake wheel during the casting process. The structure of the outer surface changed due to the friction heat during the use process. Under the multiple external forces, cracks generated at the weakness area of the surface, and extended with the horn shape.